Data processing apparatus

ABSTRACT

A data processing apparatus  100 , to reduce power consumption for processing and wirelessly transmitting continuous data to a data reproducing apparatus  200 , comprises a first signal processing unit  120  processing data stored in a data storage unit  110 , a first wireless communication unit  140  wirelessly transmitting the processed data to the data reproducing apparatus, a signal processing control unit  150  controlling the first signal processing unit  120  so as to work intermittently by processing at a speed faster than real-time processing, a clock/power control unit  160  controlling supplies of clock and power to the first signal processing unit  120  and the signal processing control unit  150  during a non-operating period of the intermittent operation, and a start-up control unit  180  requesting a release of restrictions to the clock/power control unit  160  and a transfer to an operating time period of the intermittent operation to the signal processing control unit  150  based on the amount of data stored in a received data storage unit  230.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a data processing apparatus, especiallyto a data processing apparatus for processing audio-visual data andbroadcast signals to be reproduced.

BACKGROUND ART OF THE INVENTION

As a typical conventional data processing apparatus, a transmittingapparatus 105 as shown in FIG. 8 comprises a content data storage unit115 for storing various types of content data received through anetwork, a signal processing unit 125 for converting the content datainto a specified format signal reproducible on a receiving apparatus205, a transmitting data storage unit 135 for storing the convertedspecified format signal, and a wireless communication unit 145 forwirelessly transmitting the converted specified format signal stored inthe transmitting data storage unit 135 to the receiving apparatus 205functioning as a data reproducing apparatus. The conventional dataprocessing apparatus provides an excellent operability by wirelesscommunication between the data processing apparatus and the datareproducing apparatus, thereby omitting cable connecting works and cabledisconnecting works. (See Patent Document 1)

Another conventional data processing apparatus as shown in FIG. 9comprises a broadcast wave receiving unit 196 for receiving a broadcastwave, a signal processing unit 126 for decoding data received by thebroadcast wave receiving unit 196, an output data storage unit 136 forstoring decoded data decoded in the signal processing unit 126, anoutput unit 146 for outputting the data stored in the output datastorage unit 136, a control unit 156 for controlling operations of eachof the units of the apparatus, a power unit 166 for controlling powersupplies for the broadcast wave receiving unit 196, the signalprocessing unit 126 and the output data storage unit 136, and a timerunit 176 for triggering the control unit 156 to start up. The aboveconventional data processing apparatus receives and decodes thebroadcast data that is updated a few times per day by intermittentlyoperating the broadcast wave receiving unit 196 and the signalprocessing unit 126. (See Patent Document 2)

In the conventional data processing apparatus, the broadcast wavereceiving unit 196, the data processing unit 126 and the output datastorage unit 136 are powered by the power unit 166 controlled by thecontrol unit 156 which is triggered by the timer unit 176 at the time ofreceiving the broad cast data.

Then, a broadcast wave received by the broadcast wave receiving unit 196is decoded in the signal processing unit 126, and is stored in theoutput data storage unit 136. After completing the above processes, thecontrol unit 156 controls the broadcast wave receiving unit 196, thesignal processing unit 126 and the output data storage unit 136 to stopprocessing and controls the power unit 166 so that the power unit 166stops supplying the power.

As above explained, the conventional data processing apparatus decreasesthe power consumption in a stand-by state by stopping the supply ofpower during a non-operating time period between intermittentoperations.

-   [Patent Document 1] Japanese Patent Laid-Open Publication (Kokai)    No. 2007-36886-   [Patent Document 2] Japanese Patent Laid-Open Publication (Kokai)    No. 11-122586

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

The data processing apparatus disclosed in Patent Document 1, however,has a problem in that the power consumption is not decreased because ofa so-called offset current consumed by merely supplying an electricpower and a clock signal to each unit as the apparatus is always active,though the operability of the apparatus is improved by making wirelesscommunication between the data processing apparatus and the datareproducing apparatus.

The data processing apparatus disclosed in Patent Document 2 has aproblem in that the power consumption is not decreased when applied forprocessing continuous data, for example, when the apparatus reproducesaudio-visual data or a broadcast signal, though the apparatus decreasesthe power consumption when applied for receiving data renewed a fewtimes per day.

In order to solve the problems mentioned above, it is an object of thepresent invention to provide a data processing apparatus enabling thepower consumption to be decreased for processing and wirelesslytransmitting continuous data such as audio-visual data and a broadcastsignal to a data reproducing apparatus.

Means for Solving the Problem

A data processing apparatus according to the present invention is anapparatus which processes data to be transmitted to a data reproducingapparatus which reproduces received data in real-time processing whiletemporarily storing the received data in a received data storage unit,comprising:

a data storage unit for storing data;

a signal processing unit for reading out and processing the data storedin said data storage unit;

a wireless communication unit for wirelessly transmitting the dataprocessed in said signal processing unit to said data reproducingapparatus;

a signal processing control unit for controlling said signal processingunit so that said signal processing unit is able to work intermittentlyby processing data at a processing speed faster than a real-timeprocessing speed;

a clock/power control unit for controlling a supply of at least one ofclock signals and power supplies to said signal processing unit and saidsignal processing control unit so that the power consumption of saidsignal processing unit and said signal processing control unit isdecreased by controlling the supply of at least one of the clock signalsand the power supplies to at least one part of said signal processingunit and said signal processing control unit during a non-operating timeperiod of said intermittent operation; anda start-up control unit for controlling a start-up process to request arelease of controlling the supply of at least one of the clock signalsand the power supplies to at least one part of said signal processingunit and said signal processing control unit to said clock/power controlunit, and to request transferring to an operating time period of saidintermittent operation to said signal processing control unit based onan amount of data stored in said received data storage unit.

Effect of the Invention

The present invention can provide a data processing apparatus enablingthe power consumption to be decreased for processing and wirelesslytransmitting signals of continuous data such as audio-visual data and abroadcast signal to a data reproducing apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a data processing apparatus and a datareproducing apparatus according to a first embodiment of the presentinvention.

FIG. 2 is a timing chart of the data processing apparatus and the datareproducing apparatus according to the first embodiment of the presentinvention.

FIG. 3 is a block diagram of a data processing apparatus and a datareproducing apparatus according to a second embodiment of the presentinvention.

FIG. 4 is a block diagram of a data processing apparatus and a datareproducing apparatus according to a third embodiment of the presentinvention.

FIG. 5 is a timing chart of the data processing apparatus and the datareproducing apparatus according to the third embodiment of the presentinvention.

FIG. 6 is a block diagram of a data processing apparatus and a datareproducing apparatus according to a fourth embodiment of the presentinvention.

FIG. 7 is a timing chart of the data processing apparatus and the datareproducing apparatus according to the fourth embodiment of the presentinvention.

FIG. 8 is a block diagram of a conventional data processing apparatusand a data receiving apparatus.

FIG. 9 is a block diagram of another conventional data processingapparatus.

EXPLANATIONS OF LETTERS AND NUMERALS

-   100, 300, 500, 700: Data Processing Apparatus-   105: Transmitting Apparatus-   110: Data Storage Unit-   115: Content Data Storage Unit-   120: First signal Processing Unit-   125, 126: Signal Processing Unit-   130: Sending Data Storage Unit-   135: Transmitting Data Storage Unit-   136: Output Data Storage Unit-   140: First Wireless Communication Unit-   145: Wireless Communication Unit-   146: Output Unit-   150: Signal Processing Control Unit-   156: Control Unit-   160: Clock/Power Control Unit-   166: Power Unit-   170: Trigger Signal Generating Unit-   176: Timer Unit-   180: Start-Up Control Unit-   190: Transmitting Data Monitoring Unit-   196: Broadcast Receiving Unit-   200, 400, 600, 800: Data Reproducing Apparatus-   205: Receiving Apparatus-   220: Second Data Processing Unit-   230: Received Data Storage Unit-   240: Second Wireless Communication Unit-   290: Received Data Monitoring Unit

PREFERRED EMBODIMENT OF THE INVENTION

Hereafter, embodiments of the present invention will be explained withreference to the attached drawings.

First Embodiment

FIG. 1 shows a data processing apparatus and a data reproducingapparatus according to the first embodiment of the present invention.

As shown in FIG. 1, a data processing apparatus 100 comprises a datastorage unit 110 for storing data, a first signal processing unit 120for reading out and processing the data stored in the data storage unit110, a first wireless communication unit 140 for wirelessly transmittingthe data processed in the first signal processing unit 120 to a datareproducing apparatus 200, a signal processing control unit 150 forcontrolling the first signal processing unit 120 so as to workintermittently, a clock/power control unit 160 for controlling a supplyof at least one of clock signals and power supplies to at least one partof the first signal processing unit 120 and the signal processingcontrol unit 150, a start-up control unit 180 for controlling theclock/power control unit 160, and a trigger signal generating unit 170for generating a trigger signal to the start-up control unit 180 at atiming when the clock/power control unit 160 is to be controlled.

Further, the data reproducing apparatus 200 comprises a second wirelesscommunication unit 240 for receiving the data wirelessly transmittedfrom the first wireless communication unit 140, a received data storageunit 230 for temporarily storing the data received by the secondwireless communication unit 240, and a second signal processing unit 220for real-time processing and outputting the data read out from thereceived data storage unit 230.

In this embodiment, the data processing apparatus 100 is a mobile phone,the data reproducing apparatus 200 is a stereo headphones for a wirelesscommunication system such as Bluetooth (Registered Trademark), and thedata reproducing apparatus 200 reproduces music data stored in the dataprocessing apparatus 100 wirelessly transmitted to the data reproducingapparatus 200.

The data storage unit 110 is composed of a memory card. The data storedin the data storage unit 110 is compressed audio data encoded in AAC(Advanced Audio Coding).

The first signal processing unit 120 is comprised of a DSP (DigitalSignal Processor), and works so as to decode the compressed data storedin the data storage unit 110 to corresponding PCM (Pulse CodeModulation) data by a software process of the DSP.

Further, the first signal processing unit 120 works so as to encode thePCM data to SBC (Sub-band Coding) data which can be reproduced by thedata reproducing apparatus 200, and then to generate a plurality ofpacket data by performing a protocol process according to thecommunication protocol of the Bluetooth.

The first wireless communication unit 140 and the second wirelesscommunication unit 240 work so as to send/receive the packet data byexecuting wireless communication compliant with the Bluetoothspecifications.

The signal processing control unit 150 is composed of a processor suchas a microcomputer system to control each unit of the data processingapparatus 100, and works so as to control, for example, the first signalprocessing unit 120 to start or stop processing.

Especially, the signal processing control unit 150 works so as tocontrol the first signal processing unit 120 so that the first signalprocessing unit 120 works intermittently by processing data at a speedfaster than a real-time processing speed.

For more detail, the signal processing control unit 150 works so as toindicate an amount of data to be processed by the first signalprocessing unit 120, and then request a halt command to the start-upcontrol unit 180 after receiving information on completion of processingdata of the indicated amount from the first signal processing unit 120.Thereafter, the signal processing control unit 150 works so as toindicate the amount of data to be processed to the first signalprocessing unit 120 again when receives a start-up command from thestart-up control unit 180.

As a result, the first signal processing unit 120 intermittently worksso that the active state where the data is being processed and the haltstate where the data processing is halted are repeated alternately.

The trigger signal generating unit 170 having a timer, works so as toestimate a timing when the amount of data stored in the received datastorage unit 230 becomes less than a threshold amount based on thetransmitting rate of the packet data transmitted from the first wirelesscommunication unit 140 and the data reading out speed read out inreal-time by the second signal processing unit 220, and to output atrigger signal at the timing to the start-up control unit 180.

Where, the threshold amount is preliminary determined so that the amountof data stored in the received data storage unit 230 which is read outin real-time processing by the second signal processing unit 220 doesnot reach to null.

The start-up control unit 180 works so as to execute a halt controlprocess for outputting a restriction request signal which requests therestriction of the supply of at least one of the clock signals and thepower supplies supplied to at least one part of the first signalprocessing unit 120 and the signal processing control unit 150 to theclock/power control unit 160 in accordance with a halt request from thesignal processing control unit 150. Where, the at least one part of thesignal processing control unit 150 includes a part for controlling thefirst signal processing unit 120.

Further, the start-up control unit 180 works so as to execute a start-upcontrol process to output a release request signal which requests therelease of the restriction required during the halt control process tothe clock/power control unit 160 in accordance with the trigger signaloutput from the trigger signal generating unit 170, and to force thesignal processing unit 150 to transfer to an operating time period inthe intermittent operation.

The clock/power control unit 160 works so as to reduce the powerconsumption of the data processing apparatus 100 by restricting thesupply of at least one of the clock signals and the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150 in accordance with therestriction request signal output from the start-up control unit 180.Further, the clock/power control unit 160 works so as to release therestriction in accordance with the release request signal output fromthe start-up control unit 180.

The clock/power control unit 160 works so as to control a clockgenerator, not shown, for generating the clock signals so that the clockgenerator performs any one of stopping the supply of the clock signals,lowering the frequency of the clock signals or lowering the amplitude ofthe clock signals, when restricting the supply of the clock signals toat least one part of the first signal processing unit 120 and the signalprocessing control unit 150.

The clock/power control unit 160 works so as to control a power supplycircuit, not shown, for supplying the power supplies so that the powersupply circuit performs any one of stopping the supply of the powersupplies or lowering the voltage of the power supplies, when restrictingthe supply of the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150.

The received data storage unit 230 is comprised of a semiconductormemory and works so as to store the SBC data which is converted from thepacket data received by the second wireless communication unit 240.

The second signal processing unit 220 works so as to read out the SBCdata from the received data storage unit 230 in real-time processing,and output an analog audio signal which is converted from the PCM datadecoded from the SBC data read out.

Hereafter, the behavior of the data processing apparatus 100 and thedata reproducing apparatus 200 thus constructed as above will beexplained with referring to FIG. 2. Where, the data processing apparatus100 and the data reproducing apparatus 200 process data in a unit offrame which is a processing unit of the AAC data and the SBC data.

In the first operating time period, the data processing apparatus 100continuously performs a decoding process of a predetermined number offrames (for example, 10 frames) of the AAC data. The data processingapparatus 100 then performs an SBC process for encoding the decoded datato the SBC data, and a protocol process for converting the SBC data intopacket data.

Then, the wireless transmitting process for wirelessly transmitting thepacket data to the data reproducing apparatus 200 is performed. When thewireless transmitting process is completed, the data processingapparatus 100 is transferred into a waiting time period, i.e. anon-operating time period, of the intermittent operation. In the waitingtime period, the data processing apparatus 100 goes into a power savingstate where the supply of the clock signals and the power supplies to atleast one part of the first signal processing unit 120 and the signalprocessing control unit 150 is stopped.

On the other hand, the data reproducing apparatus 200 continuouslyperforms a reproducing process in real-time processing comprised of adecoding process for decoding the SBC data obtained from the packet datareceived from the data processing apparatus 100 and a converting processfor converting the PCM data decoded from the SBC data into an analogsignal. Therefore, the SBC data stored in the received data storage unit230 is read out as needed and consumed by the second signal processingunit 220.

As a result, the amount of data stored in the received data storage unit230 is rapidly increased, because the data, the amount thereof is morethan that of the data processed in the second signal processing unit220, are transmitted from the data processing apparatus 100 between thetime T1 and the time T2.

On the other hand, the amount of data stored in the received datastorage unit 230 decreases after the time T2 because the transmission ofdata from the data processing apparatus 100 is halted, and the secondsignal processing unit 220 continuously reads out the data stored in thereceived data storage unit 230.

When the timing of the time T3 at which the amount of data stored in thereceived data storage unit 230 becomes less than a threshold amount isdetermined by the trigger signal generating unit 170, the dataprocessing apparatus 100 resumes processing data and starts transmittingthe processed data again at the time T4. Where, the threshold amount forthe amount of data stored in the received data storage unit 230 isdetermined so that the amount of data stored in the received datastorage unit 230 does not reach to null at the time T4.

The data processing apparatus 100 and the data reproducing apparatus 200work as above-explained, thus continuous data reproducing is achievedwithout drying out the data stored in the received data storage unit230.

For example, the reproducing time for reproducing 10 frames of the datasampled at a 48 kHz sampling frequency is about 200 milliseconds, andcontinuous data reproducing will be achieved if the data processingapparatus 100 can finish the data processing within this 200milliseconds. When the first signal processing unit 120 can decode thedata 10 times faster than normal, the data included in 10 frames will beprocessed in 20 milliseconds.

Further, if the data processing apparatus 100 can complete each of theSBC process and the wireless transmitting process in 10 milliseconds,the apparatus can complete all processes from the decoding process tothe wireless transmitting process in a total of 40 milliseconds.Therefore, if the apparatus can complete the process in 40 millisecondsduring this 200 milliseconds time period, an 80% of 200 millisecondsbecomes a waiting time period.

The data processing apparatus 100 according to the first embodiment ofthe present invention as above explained restricts at least one of theclock signals and the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150during the waiting time period of the intermittent operation, thus thepower consumption for processing the data of musical content andwirelessly transmitting the data to the data reproducing apparatus 200can be reduced.

In the above embodiment, the case where the data processing apparatus100 is comprised of a mobile phone is explained. But the presentinvention is not limited to this case. The data processing apparatus 100may be composed of a mobile audio-visual terminal such as a portablemusic player.

Further, in the above embodiment, the case where the first wirelesscommunication unit 140 and the second wireless communication unit 240execute wireless communication compliant with the Bluetoothspecifications is explained. But the present invention is not limited tothis case. The first wireless communication unit 140 and the secondwireless communication unit 240 may execute wireless communicationcompliant with a wireless communication system which allows transmissionof audio-visual data such as an infrared communication.

Moreover, in the above embodiment, the case where the data storage unit110 is composed of a memory card is explained. But the present inventionis not limited to this case. The data storage unit 110 may be composedof a storage medium capable of storing audio-visual data such as amagnetic tape, a magnetic disk, a semiconductor memory, or a hard disk.

Further, in the above embodiment, the case where the data stored in thedata storage unit 110 is the compressed audio data encoded in AAC isexplained. But the present invention is not limited to this case. Thedata stored in the data storage unit 110 may be compressed data ofdigital audio data such as MP3 (MPEG Audio Layer-3) data.

Moreover, the data stored in the data storage unit 110 may be movingimage data such as MPEG-4 video data or still image data such as JPEG(Joint Photographic Experts Group).

Further, the data stored in the data storage unit 110 may be acryptograph encrypted in the DES (Data Encryption Standard) or the AES(Advanced Encryption Standard). In this case, the first signalprocessing unit 120 is configured so as to further perform an encryptiondecoding process.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 performs the decoding process of AAC, the SBCprocess, and the protocol process is explained. But the presentinvention is not limited to this case. The first signal processing unit120 may perform a part of the above processes, so long as the datareproducing apparatus 200 can reproduce the data.

Additionally, in the above embodiment, the case where the second signalprocessing unit 220 performs the converting process to analog signals isexplained. But, the present invention is not limited to this case. Thesecond signal processing unit 220 may not perform the converting processto analog signals when the output unit of the second signal processingunit 220 is a unit which requires inputting digital data such as aliquid crystal display panel.

Further, in the above embodiment, the case where the first signalprocessing unit 120 performs the transcoding process from the AAC datato the SBC data is explained. But, the present invention is not limitedto this case. The first signal processing unit 120 may perform thefollowing processes;

a frequency converting process for converting the sampling frequency oforiginal data so that the data reproducing apparatus 200 can reproducethe frequency converted data when the apparatus does not accept thesampling frequency of the original data,

a spatial resolution converting process for converting the spatialresolution of original data so that the data reproducing apparatus 200can reproduce the spatial resolution converted data when the apparatusdoes not accept the spatial resolution of the original data,a frame rate converting process for converting the frame rate oforiginal data so that the data reproducing apparatus 200 can reproducethe frame rate converted data when the apparatus does not accept theframe rate of the original data, anda format converting process for converting the format of original dataso that the data reproducing apparatus 200 can reproduce the formatconverted data when the apparatus does not accept the format of theoriginal data.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 is composed of a DSP is explained. But, the presentinvention is not limited to this case. The first signal processing unit120 may be composed of another type of processors such as a CPU (CentralProcessing Unit), or partially or wholly by hardware.

Further, in the above embodiment, the case where the data processingapparatus 100 processes 10 frames of the data during one operating timeperiod is explained. But, the present invention is not limited to thiscase.

However, it is preferable that the number of frames to be processedduring one operating time period be large, because an overhead processsuch as the clock control process and the power supply control processis required to transfer from an operating time period to a waiting timeperiod or vice versa, and the load for performing the overhead processbecomes significantly heavy when frequent transferring is necessary.

Second Embodiment

FIG. 3 shows a data processing apparatus and a data reproducingapparatus according the second embodiment of the present invention. Notethat the same reference numerals as those of the first embodiment of thepresent invention are applied to the same constituent elements as thoseof the data processing apparatus 100 and the data reproducing apparatus200 of the first embodiment.

As shown in FIG. 3, a data processing apparatus 300 comprises a datastorage unit 110 for storing data, a first signal processing unit 120for reading out and processing the data stored in the data storage unit110, a first wireless communication unit 140 for wirelessly transmittingthe data processed in the first signal processing unit 120 to a datareproducing apparatus 400, a signal processing control unit 150 forcontrolling the first signal processing unit 120 so as to workintermittently, a clock/power control unit 160 for controlling a supplyof at least one of clock signals and power supplies to at least one partof the first signal processing unit 120 and the signal processingcontrol unit 150, and a start-up control unit 180 for controlling theclock/power control unit 160.

Further, the data reproducing apparatus 400 comprises a second wirelesscommunication unit 240 for receiving the data wirelessly transmittedfrom the first wireless communication unit 140, a received data storageunit 230 for temporarily storing the data received by the secondwireless communication unit 240, a second signal processing unit 220 forreal-time processing and outputting the data read out from the receiveddata storage unit 230, and a received data monitoring unit 290 formonitoring the amount of data stored in the received data storage unit230.

In this embodiment, the data processing apparatus 300 is a mobile phone,the data reproducing apparatus 400 is a stereo headphones for a wirelesscommunication system such as Bluetooth, and the data reproducingapparatus 400 reproduces music data stored in the data processingapparatus 300 which is wirelessly transmitted to the data reproducingapparatus 300.

The data storage unit 110 is composed of a memory card. The data storedin the data storage unit 110 is compressed audio data encoded in AAC(Advanced Audio Coding).

The first signal processing unit 120 is comprised of a DSP (DigitalSignal Processor), and works so as to decode the compressed data storedin the data storage unit 110 to corresponding PCM (Pulse CodeModulation) data by a software process of the DSP.

Further, the first signal processing unit 120 works so as to encode thePCM data to SBC (Sub-band Coding) data which can be reproduced by thedata reproducing apparatus 400, and then to generate a plurality ofpacket data by performing a protocol process according to thecommunication protocol of the Bluetooth.

The first wireless communication unit 140 and the second wirelesscommunication unit 240 work so as to send/receive the packet data byexecuting wireless communication compliant with the Bluetoothspecifications.

And, the second wireless communication unit 240 works so as to send adata transmit request signal for requesting a transmission of packetdata to the first wireless communication unit 140 with a commandreceived from the received data monitoring unit 290.

The signal processing unit 150 is composed of a processor such as amicrocomputer system to control each unit of the data processingapparatus 300, and works so as to control, for example, the first signalprocessing unit 120 to start or stop processing.

Especially, the signal processing control unit 150 works so as tocontrol the first signal processing unit 120 so that the first signalprocessing unit 120 can work intermittently by processing data at aspeed faster than the real-time processing.

For more detail, the signal processing control unit 150 works so as toindicate an amount of data to be processed to the first signalprocessing unit 120, and then request a halt command to the start-upcontrol unit 180 after receiving information on completion of processingdata of the indicated amount from the first signal processing unit 120.Thereafter, the signal processing control unit 150 works so as toindicate the amount of data to be processed to the first signalprocessing unit 120 again when receives a start-up command from thestart-up control unit 180.

As a result, the first signal processing unit 120 intermittently worksso that the active state where the data is being processed and the haltstate where the data processing is halted are repeated alternately.

The start-up control unit 180 works so as to execute a halt controlprocess to output a restriction request signal which requests therestriction of the supply of at least one of the clock signals and thepower supplies supplied to at least one part of the first signalprocessing unit 120 and the signal processing control unit 150 to theclock/power control unit 160 in accordance with a halt request from thesignal processing control unit 150. Where, the at least one part of thesignal processing control unit 150 includes a part for controlling thefirst signal processing unit 120.

Further, the start-up control unit 180 works so as to execute a start-upcontrol process to output a release request signal which requests therelease of restricting output during the halt control process to theclock/power control unit 160 in accordance with the data transmitrequest signal received by the first wireless communication unit 140,and to force the signal processing unit 150 to transfer to an operatingtime period in the intermittent operation.

The clock/power control unit 160 works so as to reduce the powerconsumption of the data processing apparatus 300 by restricting thesupply of at least one of the clock signals and the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150 in accordance with therestriction request signal output from the start-up control unit 180.Further, the clock/power, control unit 160 works so as to release therestriction in accordance with the release request signal output fromthe start-up control unit 180.

The clock/power control unit 160 works so as to control a clockgenerator, not shown, for generating the clock signals so that the clockgenerator performs any one of stopping the supply of the clock signals,lowering the frequency of the clock signals or lowering the amplitude ofthe clock signals, when restricting the supply of the clock signals toat least one part of the first signal processing unit 120 and the signalprocessing control unit 150.

The clock/power control unit 160 works so as to control a power supplycircuit, not shown, for supplying the power supplies so that the powersupply circuit performs any one of stopping the supply of the powersupplies or lowering the voltage of the power supplies, when restrictingthe supply of the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150.

The received data storage unit 230 is comprised of a semiconductormemory and works so as to store the SBC data which is converted from thepacket data received by the second wireless communication unit 240.

The second signal processing unit 220 works so as to read out the SBCdata from the received data storage unit 230 in real-time processing,and output an analog audio signal which is converted from the PCM datadecoded from the SBC data read out.

The received data monitoring unit 290 works so as to monitor the amountof data stored in the received data storage unit 230, and to order tosend a data transmit request signal to the second wireless communicationunit 240 when the amount of data stored in the received data storageunit 230 is lowered below a threshold amount.

Where, the threshold amount is preliminary determined so that the amountof data stored in the received data storage unit 230 which is read outin real-time processing by the second signal processing unit 220 doesnot reach to null.

The description for explaining the operation of the data processingapparatus 300 and the data reproducing apparatus 400 configured as aboveis omitted, because the operation is substantially the same as thosedescribed with reference to FIG. 2 for the data processing apparatus 100and the data reproducing apparatus 200 according to the first embodimentof the present invention.

The data processing apparatus 300 according to the second embodiment ofthe present invention as above explained restricts at least one of theclock signals and the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150during the waiting time period of the intermittent operation, thus thepower consumption for processing the data of musical content andwirelessly transmitting the data to the data reproducing apparatus 200can be reduced.

Further, the data processing apparatus 300 according to the secondembodiment of the present invention can transmit the data to the datareproducing apparatus 400 in a more precise timing, because the dataprocessing apparatus 300 performs a start-up process in response to thedata transmit request signal sent from the data reproducing apparatus400 in accordance with the order of the received data monitoring unit290 for monitoring the amount of data stored in the received datastorage unit 230.

In the above embodiment, the case where the data processing apparatus300 is comprised of a mobile phone is explained. But the presentinvention is not limited to this case. The data processing apparatus 100may be composed of a mobile audio-visual terminal such as a portablemusic player.

Further, in the above embodiment, the case where the first wirelesscommunication unit 140 and the second wireless communication unit 240execute wireless communication compliant with the Bluetoothspecifications is explained. But the present invention is not limited tothis case. The first wireless communication unit 140 and the secondwireless communication unit 240 may execute wireless communicationcompliant with a wireless communication system which allows transmissionof audio-visual data such as an infrared communication.

Moreover, in the above embodiment, the case where the data storage unit110 is composed of a memory card is explained. But the present inventionis not limited to this case. The data storage unit 110 may be composedof a storage medium capable of storing audio-visual data such as amagnetic tape, a magnetic disk, a semiconductor memory, or a hard disk.

Further, in the above embodiment, the case where the data stored in thedata storage unit 110 is the compressed audio data encoded in AAC isexplained. But the present invention is not limited to this case. Thedata stored in the data storage unit 110 may be compressed data ofdigital audio data such as MP3 (MPEG Audio Layer-3) data.

Moreover, the data stored in the data storage unit 110 may be movingimage data such as MPEG-4 video data or still image data such as JPEG(Joint Photographic Experts Group).

Additionally, the data stored in the data storage unit 110 may be acryptograph encrypted in the DES (Data Encryption Standard) or the AES(Advanced Encryption Standard). In this case, the first signalprocessing unit 120 is configured so as to further perform an encryptiondecoding process.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 performs the decoding process of AAC, the SBCprocess, and the protocol process is explained. But the presentinvention is not limited to this case. The first signal processing unit120 may perform a part of the above processes, so long as the datareproducing apparatus 400 can reproduce the data.

Additionally, in the above embodiment, the case where the second signalprocessing unit 220 performs the converting process to analog signals isexplained. But, the present invention is not limited to this case. Thesecond signal processing unit 220 may not perform the converting processto analog signals when the output unit of the second signal processingunit 220 is a unit which requires inputting digital data such as aliquid crystal display panel.

Further, in the above embodiment, the case where the first signalprocessing unit 120 performs the transcoding process from the AAC datato the SBC data is explained. But, the present invention is not limitedto this case. The first signal processing unit 120 may perform followingprocesses;

a frequency converting process for converting the sampling frequency oforiginal data so that the data reproducing apparatus 400 can reproducethe frequency converted data when the apparatus does not accept thesampling frequency of the original data,

a spatial resolution converting process for converting the spatialresolution of original data so that the data reproducing apparatus 400can reproduce the spatial resolution converted data when the apparatusdoes not accept the spatial resolution of the original data,a frame rate converting process for converting the frame rate oforiginal data so that the data reproducing apparatus 400 can reproducethe frame rate converted data when the apparatus does not accept theframe rate of the original data, anda format converting process for converting the format of original dataso that the data reproducing apparatus 400 can reproduce the formatconverted data when the apparatus does not accept the format of theoriginal data.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 is composed of a DSP is explained. But, the presentinvention is not limited to this case. The first signal processing unit120 may be composed of another type of processors such as a CPU (CentralProcessing Unit), or partially or wholly by hardware.

Further, in the above embodiment, the case where the data processingapparatus 300 processes 10 frames of the data during one operating timeperiod is explained. But, the present invention is not limited to thiscase.

However, it is preferable that the number of frames to be processedduring one operating time period be large, because an overhead processsuch as the clock control process and the power supply control processis required to transfer from an operating time period to a waiting timeperiod or vice versa, and the load for performing the overhead processbecomes significantly heavy when frequent transferring is necessary.

Third Embodiment

FIG. 4 shows a data processing apparatus and a data reproducingapparatus according the third embodiment of the present invention. Notethat the same reference numerals as those of the second embodiment ofthe present invention are applied to the same constituent elements asthose of the data processing apparatus 300 and the data reproducingapparatus 400 of the second embodiment.

As shown in FIG. 4, a data processing apparatus 500 comprises a datastorage unit 110 for storing data, a first signal processing unit 120for reading out and processing the data stored in the data storage unit110, a sending data storage unit 130 for temporarily storing the dataprocessed in the first signal processing unit 120, a first wirelesscommunication unit 140 for wirelessly transmitting the data stored inthe sending data storage unit 130 to a data reproducing apparatus 600, asignal processing control unit 150 for controlling the first signalprocessing unit 120 so as to work intermittently, a clock/power controlunit 160 for controlling a supply of at least one of clock signals andpower supplies to at least one part of the first signal processing unit120 and the signal processing control unit 150, and a start-up controlunit 180 for controlling the clock/power control unit 160.

Further, the data reproducing apparatus 600 comprises a second wirelesscommunication unit 240 for receiving the data wirelessly transmittedfrom the first wireless communication unit 140, a received data storageunit 230 for temporarily storing the data received by the secondwireless communication unit 240, a second signal processing unit 220 forreal-time processing and outputting the data read out from the receiveddata storage unit 230, and a received data monitoring unit 290 formonitoring the amount of data stored in the received data storage unit230.

In this embodiment, the data processing apparatus 500 is a mobile phone,the data reproducing apparatus 600 is a stereo headphones for a wirelesscommunication system such as Bluetooth, and the data reproducingapparatus 600 reproduces music data stored in the data processingapparatus 500 which is wirelessly transmitted to the data reproducingapparatus 600.

The data storage unit 110 is composed of a memory card. The data storedin the data storage unit 110 is compressed audio data encoded in AAC(Advanced Audio Coding).

The first signal processing unit 120 is comprised of a DSP (DigitalSignal Processor), and works so as to decode the compressed data storedin the data storage unit 110 to corresponding PCM (Pulse CodeModulation) data by a software process of the DSP.

Further, the first signal processing unit 120 works so as to encode thePCM data to SBC (Sub-band Coding) data which can be reproduced by thedata reproducing apparatus 600, and then to generate a plurality ofpacket data by performing a protocol process according to thecommunication protocol of the Bluetooth.

The first wireless communication unit 140 and the second wirelesscommunication unit 240 work so as to send/receive the packet data byexecuting wireless communication compliant with the Bluetoothspecifications.

Where, the first wireless communication unit 140 works so as towirelessly transmit the data stored in the sending data storage unit 130while the first signal processing unit 120 is performing the dataprocessing.

And, the second wireless communication unit 240 works so as to send adata transmit request signal for requesting a transmission of packetdata to the first wireless communication unit 140 with a commandreceived from the received data monitoring unit 290.

The signal processing unit 150 is composed of a processor such as amicrocomputer system to control each unit of the data processingapparatus 300, and works so as to control, for example, the first signalprocessing unit 120 to start or stop processing.

Especially, the signal processing control unit 150 works so as tocontrol the first signal processing unit 120 so that the first signalprocessing unit 120 can work intermittently by processing data at aspeed faster than the real-time processing.

For more detail, the signal processing control unit 150 works so as toindicate an amount of data to be processed to the first signalprocessing unit 120, and then to request a halt command to the start-upcontrol unit 180 after receiving information on completion of processingdata of the indicated amount from the first signal processing unit 120.Thereafter, the signal processing control unit 150 works so as toindicate the amount of data to be processed to the first signalprocessing unit 120 again when receives a start-up command from thestart-up control unit 180.

As a result, the first signal processing unit 120 intermittently worksso that the active state where the data is being processed and the haltstate where the data processing is halted are repeated alternatively.

The start-up control unit 180 works so as to execute a halt controlprocess to output a restriction request signal which restricts thesupply of at least one of the clock signals and the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150. Where, the at least one partof the signal processing control unit 150 includes a part forcontrolling the first signal processing unit 120.

Further, the start-up control unit 180 works so as to execute a start-upcontrol process to output a release request signal which requests therelease of restricting output during the halt control process to theclock/power control unit 160 in accordance with the data transmitrequest signal received by the first wireless communication unit 140,and to force the signal processing unit 150 to transfer to an operatingtime period in the intermittent operation.

The clock/power control unit 160 works so as to reduce the powerconsumption of the data processing apparatus 500 by restricting thesupply of at least one of the clock signals and the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150 in accordance with therestriction request signal output from the start-up control unit 180.Further, the clock/power control unit 160 works so as to release therestriction in accordance with the release request signal output fromthe start-up control unit 180.

The clock/power control unit 160 works so as to control a clockgenerator, not shown, for generating the clock signals so that the clockgenerator performs any one of stopping the supply of the clock signals,lowering the frequency of the clock signals or lowering the amplitude ofthe clock signals, when restricting the supply of the clock signals toat least one part of the first signal processing unit 120 and the signalprocessing control unit 150.

The clock/power control unit 160 works so as to control a power supplycircuit, not shown, for supplying the power supplies so that the powersupply circuit performs any one of stopping the supply of the powersupplies or lowering the voltage of the power supplies, when restrictingthe supply of the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150.

The received data storage unit 230 is comprised of a semiconductormemory and works so as to store the SBC data which is converted from thepacket data received by the second wireless communication unit 240.

The second signal processing unit 220 works so as to read out the SBCdata from the received data storage unit 230 in real-time processing,and output an analog audio signal which is converted from the PCM datadecoded from the SBC data read out.

The received data monitoring unit 290 works so as to monitor the amountof data stored in the received data storage unit 230, and to order tosend a data transmit request signal to the second wireless communicationunit 240 when the amount of data stored in the received data storageunit 230 is lowered below a threshold amount.

Where, the threshold amount is preliminary determined so that the amountof data stored in the received data storage unit 230 which is read outin real-time processing by the second signal processing unit 220 doesnot reach to null.

Hereafter, the behavior of the data processing apparatus 500 and thedata reproducing apparatus 600 thus constructed as above will beexplained with referring to FIG. 5. Where, the data processing apparatus500 and the data reproducing apparatus 600 process data in a unit offrame which is a processing unit of the AAC data and the SBC data.

In the second operating time period, the data processing apparatus 500continuously performs a decoding process of a predetermined number offrames (for example, 10 frames) of the AAC data. The data processingapparatus 500 then performs an SBC process for encoding the decoded datato the SBC data, a protocol process for converting the SBC data intopacket data, and storing process for storing the packet data in thesending data storage unit 130.

The data processing apparatus 500 performs the wireless transmittingprocess to wirelessly transmit the packet data stored in the sendingdata storage unit 130 to the data reproducing apparatus 600 whileperforming the above processes.

Note, in the wireless transmitting process, the data processingapparatus 500 wirelessly transmits the packet data which has beenprocessed in the first signal processing unit 120 and stored in thesending data storage unit 130 during the previous operating time period.

For example, in the third operating time period, the packet data storedin the sending data storage unit 130 during the second operating timeperiod is transmitted.

When the wireless transmitting process and the processes of the firstsignal processing unit 120 are completed, the data processing apparatus500 is transferred into a waiting time period of the intermittentoperation.

In the waiting time period, the data processing apparatus 500 goes intoa power saving state where the supply of the clock signal and the powersupplies to at least one part of the first signal processing unit 120and the signal processing control unit 150 is stopped.

On the other hand, the data reproducing apparatus 600 continuouslyperforms a reproducing process in real-time processing comprised of adecoding process for decoding the SBC data obtained from the packet datareceived from the data processing apparatus 600 and a converting processfor converting the PCM data decoded from the SBC data into an analogsignal.

Therefore, the SBC data stored in the received data storage unit 230 isread out as needed and consumed by the second signal processing unit220.

As a result, the amount of data stored in the received data storage unit230 is rapidly increased, because the data, the amount thereof is morethan that of the data processed in the second signal processing unit220, are transmitted from the data processing apparatus 100 between thetime T1 and the time T2.

On the other hand, the amount of data stored in the received datastorage unit 230 decreases after the time T2 because the transmission ofdata from the data processing apparatus 500 is halted, and the secondsignal processing unit 220 continuously reads out the data stored in thereceived data storage unit 230.

When the timing of the time T3 at which the amount of data stored in thereceived data storage unit 230 becomes less than a threshold amount andthe data transmit request signal is transmitted from the datareproducing apparatus 600 to the data processing apparatus 500, the dataprocessing apparatus 500 resumes processing data and starts transmittingthe processed data again at the time T4.

Where, the threshold amount for the amount of data stored in thereceived data storage unit 230 is determined so that the amount of datastored in the received data storage unit 230 does not reach to null atthe time T4.

The data processing apparatus 500 and the data reproducing apparatus 600work as above-explained, thus continuous data reproducing is achievedwithout drying out the data stored in the received data storage unit230.

For example, the reproducing time for reproducing 10 frames of the datasampled at a 48 kHz sampling frequency is about 200 milliseconds, andcontinuous data reproducing will be achieved if the data processingapparatus 500 can finish the data processing within this 200milliseconds.

When the first signal processing unit 120 can decode the data 10 timesfaster than normal, the data included in 10 frames will be processed in20 milliseconds.

Further, if the data processing apparatus 500 can complete each of theSBC process and the wireless transmitting process in 10 milliseconds,the apparatus can complete all processes from the decoding process tothe wireless transmitting process in a total of 30 milliseconds, becausethe wireless transmitting process is performed in parallel with thedecoding process and the encoding process.

Therefore, if the apparatus can complete the process in 30 millisecondsduring this 200 milliseconds time period, an 85% of 200 millisecondsbecomes a waiting time period.

The data processing apparatus 500 according to the third embodiment ofthe present invention as above explained restricts at least one of theclock signals and the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150during the waiting time period of the intermittent operation, thus thepower consumption for processing the data of musical content andwirelessly transmitting the data to the data reproducing apparatus 600can be reduced.

Further, the data processing apparatus 500 according to the thirdembodiment of the present invention can transmit the data to the datareproducing apparatus 600 in a more precise timing, because the dataprocessing apparatus 500 performs a start-up process in response to thedata transmit request signal sent from the data reproducing apparatus600 in accordance with the order of the received data monitoring unit290 for monitoring the amount of data stored in the received datastorage unit 230.

Additionally the data processing apparatus 500 according to the thirdembodiment of the present invention achieves the waiting time period ofthe intermittent operation longer than the preceding embodiments,because the wireless transmitting process transmitting the packet datato the data reproducing apparatus 600 is performed in parallel with thedecoding process and the encoding process.

In the above embodiment, the case where the data processing apparatus500 is comprised of a mobile phone is explained. But the presentinvention is not limited to this case. The data processing apparatus 500may be composed of a mobile audio-visual terminal such as a portablemusic player.

Further, in the above embodiment, the case where the first wirelesscommunication unit 140 and the second wireless communication unit 240execute wireless communication compliant with the Bluetoothspecifications is explained. But the present invention is not limited tothis case. The first wireless communication unit 140 and the secondwireless communication unit 240 may execute wireless communicationcompliant with a wireless communication system which allows transmissionof audio-visual data such as an infrared communication.

Moreover, in the above embodiment, the case where the data storage unit110 is composed of a memory card is explained. But the present inventionis not limited to this case. The data storage unit 110 may be composedof a storage medium capable of storing audio-visual data such as amagnetic tape, a magnetic disk, a semiconductor memory, or a hard disk.

Further, in the above embodiment, the case where the data stored in thedata storage unit 110 is the compressed audio data encoded in AAC isexplained. But the present invention is not limited to this case. Thedata stored in the data storage unit 110 may be compressed data ofdigital audio data such as MP3 (MPEG Audio Layer-3) data.

Further, the data stored in the data storage unit 110 may be movingimage data such as MPEG-4 video data or still image data such as JPEG(Joint Photographic Experts Group).

Additionally, the data stored in the data storage unit 110 may be acryptograph encrypted in the DES (Data Encryption Standard) or the AES(Advanced Encryption Standard). In this case, the first signalprocessing unit 120 is configured so as to further perform an encryptiondecoding process.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 performs the decoding process of AAC, the SBCprocess, and the protocol process is explained. But the presentinvention is not limited to this case. The first signal processing unit120 may perform a part of the above processes, so long as the datareproducing apparatus 600 can reproduce the data.

Additionally, in the above embodiment, the case where the second signalprocessing unit 220 performs the converting process to analog signals isexplained. But, the present invention is not limited to this case. Thesecond signal processing unit 220 may not perform the converting processto analog signals when the output unit of the second signal processingunit 220 is a unit which requires inputting digital data such as aliquid crystal display panel.

Further, in the above embodiment, the case where the first signalprocessing unit 120 performs the transcoding process from the AAC datato the SBC data is explained. But, the present invention is not limitedto this case. The first signal processing unit 120 may perform followingprocesses; a frequency converting process for converting the samplingfrequency of original data so that the data reproducing apparatus 600can reproduce the frequency converted data when the apparatus does notaccept the sampling frequency of the original data, a spatial resolutionconverting process for converting the spatial resolution of originaldata so that the data reproducing apparatus 600 can reproduce thespatial resolution converted data when the apparatus does not accept thespatial resolution of the original data, a frame rate converting processfor converting the frame rate of original data so that the datareproducing apparatus 600 can reproduce the frame rate converted datawhen the apparatus does not accept the frame rate of the original data,and a format converting process for converting the format of originaldata so that the data reproducing apparatus 600 can reproduce the formatconverted data when the apparatus does not accept the format of theoriginal data.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 is composed of a DSP is explained. But, the presentinvention is not limited to this case. The first signal processing unit120 may be composed of another type of processors such as a CPU (CentralProcessing Unit), or partially or wholly by hardware.

Further, in the above embodiment, the case where the data processingapparatus 500 processes 10 frames of the data during one operating timeperiod is explained. But, the present invention is not limited to thiscase.

However, it is preferable that the number of frames to be processedduring one operating time period be large, because an overhead processsuch as the clock control process and the power supply control processis required to transfer from an operating time period to a waiting timeperiod or vice versa, and the load for performing the overhead processbecomes significantly heavy when frequent transferring is necessary.

Additionally, in this embodiment, the case where the start-up controlunit 180 performs the start-up control process in response to the datatransmit request signal sent from the data reproducing apparatus 600 isexplained. The data processing apparatus 500 of this embodiment,however, may comprise the trigger signal generating unit 170 as the sameas that of the data processing apparatus 100 of the first embodiment,and may make the start-up control unit 180 to perform the start-upcontrol process in response to the trigger signal generated in thetrigger signal generating unit 170.

Fourth Embodiment

FIG. 6 shows a data processing apparatus and a data reproducingapparatus according the fourth embodiment of the present invention. Notethat the same reference numerals as those of the first embodiment of thepresent invention are applied to the same constituent elements as thoseof the data processing apparatus 100 and the data reproducing apparatus200 of the first embodiment.

As shown in FIG. 6, a data processing apparatus 700 comprises a datastorage unit 110 for storing data, a first signal processing unit 120for reading out and processing the data stored in the data storage unit110, a sending data storage unit 130 for temporarily storing the dataprocessed in the first signal processing unit 120, a first wirelesscommunication unit 140 for wirelessly transmitting the data stored inthe sending data storage unit 130 to a data reproducing apparatus 800, asignal processing control unit 150 for controlling the first signalprocessing unit 120 so as to work intermittently, a clock/power controlunit 160 for controlling a supply of at least one of clock signals andpower supplies to at least one part of the first signal processing unit120 and the signal processing control unit 150, a start-up control unit180 for controlling the clock/power control unit 160, and a transmitteddata monitoring unit 190 for monitoring an amount of data stored in thesending data storage unit 130.

Further, the data reproducing apparatus 800 comprises a second wirelesscommunication unit 240 for receiving the data wirelessly transmittedfrom the first wireless communication unit 140, a received data storageunit 230 for temporarily storing the data received by the secondwireless communication unit 240, and a second signal processing unit 220for real-time processing and outputting the data read out from thereceived data storage unit 230.

In this embodiment, the data processing apparatus 700 is a mobile phone,the data reproducing apparatus 800 is a stereo headphones for a wirelesscommunication system such as Bluetooth, and the data reproducingapparatus 800 reproduces music data stored in the data processingapparatus 700 which is wirelessly transmitted to the data reproducingapparatus 700.

The data storage unit 110 is composed of a memory card. The data storedin the data storage unit 110 is compressed audio data encoded in AAC(Advanced Audio Coding).

The first signal processing unit 120 is comprised of a DSP (DigitalSignal Processor), and works so as to decode the compressed data storedin the data storage unit 110 to corresponding PCM (Pulse CodeModulation) data by a software process of the DSP.

Further, the first signal processing unit 120 works so as to encode thePCM data to SBC (Sub-band Coding) data which can be reproduced by thedata reproducing apparatus 800, and then to generate a plurality ofpacket data by performing a protocol process according to thecommunication protocol of the Bluetooth.

The first wireless communication unit 140 and the second wirelesscommunication unit 240 work so as to send/receive the packet data byexecuting wireless communication compliant with the Bluetoothspecifications.

Where, the first wireless communication unit 140 reads out and transmitsthe processed packet data stored in the sending data storage unit 130 inreal-time independently from the signal processing processed by thefirst signal processing unit 120.

The signal processing unit 150 is composed of a processor such as amicrocomputer system to control each unit of the data processingapparatus 700, and works so as to control, for example, the first signalprocessing unit 120 to start or stop processing.

Especially, the signal processing control unit 150 works so as tocontrol the first signal processing unit 120 so that the first signalprocessing unit 120 can work intermittently by processing data at aspeed faster than the real-time processing.

For more detail, the signal processing control unit 150 works so as toindicate an amount of data to be processed to the first signalprocessing unit 120, and then to request a halt command to the start-upcontrol unit 180 after receiving information on completion of processingdata of the indicated amount from the first signal processing unit 120.Thereafter, the signal processing control unit 150 works so as toindicate the amount of data to be processed to the first signalprocessing unit 120 again when receives start-up command from thestart-up control unit 180.

As a result, the first signal processing unit 120 intermittently worksso that the active state where the data is being processed and the haltstate where the data processing is halted are repeated alternatively.

The transmitted data monitoring unit 190 works so as to monitor theamount of data stored in the sending data storage unit 130, and output adata processing request signal to the start-up control unit 180, whenthe amount of data stored in the sending data storage unit 130 islowered below a threshold amount.

Where, the threshold amount is preliminary determined so that the amountof data stored in the sending data storage unit 130 which is read out inreal-time processing by the first wireless communication unit 140 doesnot reach to null.

While the first wireless communication unit 140 reads out the datastored in the sending data storage unit 130 in real-time processing, thesecond signal processing unit 220 reads out the data stored in thereceived data storage unit 230 in real-time. Therefore, by determiningthe threshold amount of data stored in the sending data storage unit 130so as not to reach null, the amount of data stored in the received datastorage unit 230 is prevented from reaching to null.

The start-up control unit 180 works so as to execute a halt controlprocess to output a restriction request signal which restricts thesupply of at least one of the clock signal sand the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150.

Where, the at least one part of the signal processing control unit 150includes a part for controlling the first signal processing unit 120.

Further, the start-up control unit 180 works so as to execute a start-upcontrol process to output a release request signal which requests therelease of restricting output during the halt control process to theclock/power control unit 160 in accordance with the data processingrequest signal generated by the transmitted data monitoring unit 190,and to force the signal processing unit 150 to transfer to an operatingtime period in the intermittent operation.

The clock/power control unit 160 works so as to reduce the powerconsumption of the data processing apparatus 700 by restricting thesupply of at least one of the clock signals and the power suppliessupplied to at least one part of the first signal processing unit 120and the signal processing control unit 150 in accordance with therestriction request signal output from the start-up control unit 180.Further, the clock/power control unit 160 works so as to release therestriction in accordance with the release request signal output fromthe start-up control unit 180.

The clock/power control unit 160 works so as to control a clockgenerator, not shown, for generating the clock signals so that the clockgenerator performs any one of stopping the supply of the clock signals,lowering the frequency of the clock signals or lowering the amplitude ofthe clock signals, when restricting supply of the clock signals to atleast one part of the first signal processing unit 120 and the signalprocessing control unit 150.

The clock/power control unit 160 works so as to control a power supplycircuit, not shown, for supplying the power supplies so that the powersupply circuit performs any one of stopping the supply of the powersupplies or lowering the voltage of the power supplies, when restrictingthe supply of the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150.

The received data storage unit 230 is comprised of a semiconductormemory and works so as to store the SBC data which is converted from thepacket data received by the second wireless communication unit 240.

The second signal processing unit 220 works so as to read out the SBCdata from the received data storage unit 230 in real-time processing,and output an analog audio signal which is converted from the PCM datadecoded from the SBC data read out.

Hereafter, the behavior of the data processing apparatus 700 and thedata reproducing apparatus 800 thus constructed as above will beexplained with referring to FIG. 7. Where, the data processing apparatus700 and the data reproducing apparatus 800 process data in a unit offrame which is a processing unit of the AAC data and the SBC data.

In the second operating time period, the data processing apparatus 700continuously performs a decoding process of a predetermined number offrames (for example, 10 frames) of the AAC data. The data processingapparatus 700 then performs an SBC process for encoding the decoded datato the SBC data, a protocol process for converting the SBC data intopacket data, and storing process for storing the packet data in thesending data storage unit 130.

When the process of the first signal processing unit 120 is completed,the data processing apparatus 700 is transferred into a waiting timeperiod of the intermittent operation.

In the waiting time period, the data processing apparatus 700 goes intoa power saving state where the supply of the clock signals and the powersupplies to at least one part of the first signal processing unit 120and the signal processing control unit 150 is stopped.

The wireless transmitting process for transmitting the data stored inthe sending data storage unit 130 to the data reproducing apparatus 800is independently performed in parallel with the process of the firstsignal processing unit 120. In this transmitting process, the packetdata processed by the signal processing unit 120 and stored in thesending data storage unit 130 during the previous operating time periodis read out and transmitted in real-time processing.

On the other hand, the data reproducing apparatus 800 continuouslyperforms a reproducing process in real-time processing comprised of adecoding process for decoding the SBC data obtained from the packet datafrom the data processing apparatus 700 and a converting process forconverting the PCM data decoded from the SBC data into an analog signal.

Therefore, the SBC data stored in the received data storage unit 230 isread out as needed and consumed by the second signal processing unit220.

As a result, the amount of data stored in the sending data storage unit130 is rapidly increased, because the data, the amount thereof is morethan that of the data processed in the first wireless communication unit140, are sent to the sending data storage unit 130 by the first signalprocessing unit 120 between the time T1 and the time T2.

On the other hand, the amount of data stored in the sending data storageunit 130 decreases after the time T2 because the signal processing bythe first signal processing unit 120 is halted, and the first signalprocessing unit 140 continuously reads out the data stored in thesending data storage unit 130.

When the amount of data stored in the sending data storage unit 130becomes less than a threshold amount at the time T3, and the transmitteddata monitoring unit 190 outputs a data processing request signal to thestart-up control unit 180, the first signal processing unit 120 of thedata processing apparatus 700 starts processing data again.

Where, the threshold amount for the amount of data stored in the sendingdata storage unit 130 is determined so that the amount of data stored inthe sending data storage unit 130 does not reach to null at the time T4.

The data processing apparatus 700 and the data reproducing apparatus 800work as above-explained, thus continuous data reproducing is achievedwithout drying out the data stored in the received data storage unit230.

For example, the reproducing time for reproducing 10 frames of the datasampled at a 48 kHz sampling frequency is about 200 milliseconds, andcontinuous data reproducing will be achieved if the data processingapparatus 700 can finish the data processing within this 200milliseconds.

When the first signal processing unit 120 can decode the data 10 timesfaster than normal, the data included in 10 frames will be processed in20 milliseconds.

Further, if the data processing apparatus 700 can complete each of theSBC process and the wireless transmitting process in 10 milliseconds,the apparatus can complete all processes from the decoding process tothe wireless transmitting process in a total of 30 milliseconds, becausethe wireless transmitting process is performed in parallel with thedecoding process and the encoding process.

Therefore, if the apparatus can complete the process in 30 millisecondsduring this 200 milliseconds time period, an 85% of 200 millisecondsbecomes a waiting time period.

The data processing apparatus 700 according to the forth embodiment ofthe present invention as above explained restricts at least one of theclock signals and the power supplies to at least one part of the firstsignal processing unit 120 and the signal processing control unit 150during the waiting time period of the intermittent operation, thus thepower consumption for processing the data of musical content andwirelessly transmitting the data to the data reproducing apparatus 800can be reduced.

Further, the data processing apparatus 700 according to the forthembodiment of the present invention can transmit the data to the datareproducing apparatus 800 in a more precise timing, because the dataprocessing apparatus 700 performs a start-up process in response to thedata transmit request signal sent from the transmitted data monitoringunit 190 for monitoring the amount of data stored in the sending datastorage unit 130.

Additionally the data processing apparatus 700 according to the forthembodiment of the present invention achieves the waiting time period ofthe intermittent operation longer than the preceding embodiments,because the wireless transmitting process transmitting the packet datato the data reproducing apparatus is independently performed in parallelwith the decoding process and the encoding process.

In the above embodiment, the case where the data processing apparatus700 is comprised of a mobile phone is explained. But the presentinvention is not limited to this case. The data processing apparatus 700may be composed of a mobile audio-visual terminal such as a portablemusic player.

Further, in the above embodiment, the case where the first wirelesscommunication unit 140 and the second RF transmitting unit 240 executewireless communication compliant with the Bluetooth specifications isexplained. But the present invention is not limited to this case. Thefirst wireless communication unit 140 and the second wirelesscommunication unit 240 may execute wireless communication compliant witha wireless communication system which allows transmission ofaudio-visual data such as an infrared communication.

Moreover, in the above embodiment, the case where the data storage unit110 is composed of a memory card is explained. But the present inventionis not limited to this case. The data storage unit 110 may be composedof a storage medium capable of storing the audio-visual data such as amagnetic tape, a magnetic disk, a semiconductor memory, or a hard disk.

Further, in the above embodiment, the case where the data stored in thedata storage unit 110 is the compressed audio data encoded in AAC isexplained. But the present invention is not limited to this case. Thedata stored in the data storage unit 110 may be compressed data ofdigital audio data such as MP3 (MPEG Audio Layer-3) data.

Further, the data stored in the data storage unit 110 may be movingimage data such as MPEG-4 video data or still image data such as JPEG(Joint Photographic Experts Group).

Additionally, the data stored in the data storage unit 110 may be acryptograph encrypted in the DES (Data Encryption Standard) or the AES(Advanced Encryption Standard). In this case, the first signalprocessing unit 120 is configured so as to further perform an encryptiondecoding process.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 performs the decoding process of AAC, the SBCprocess, and the protocol process is explained. But the presentinvention is not limited to this case. The first signal processing unit120 may perform a part of the above processes, so long as the datareproducing apparatus 800 can reproduce the data.

Additionally, in the above embodiment, the case where the second signalprocessing unit 220 performs the converting process to analog signals isexplained. But, the present invention is not limited to this case. Thesecond signal processing unit 220 may not perform the converting processto analog signals when the output unit of the second signal processingunit 220 is a unit which requires inputting digital data such as aliquid crystal display panel.

Further, in the above embodiment, the case where the first signalprocessing unit 120 performs the transcoding process from the AAC datato the SBC data is explained. But, the present invention is not limitedto this case. The first signal processing unit 120 may perform followingprocesses; a frequency converting process for converting the samplingfrequency of original data so that the data reproducing apparatus 800can reproduce the frequency converted data when the apparatus does notaccept the sampling frequency of the original data, a spatial resolutionconverting process for converting the spatial resolution of originaldata so that the data reproducing apparatus 800 can reproduce thespatial resolution converted data when the apparatus does not accept thespatial resolution of the original data, a frame rate converting processfor converting the frame rate of original data so that the datareproducing apparatus 800 can reproduce the frame rate converted datawhen the apparatus does not accept the frame rate of the original data,and a format converting process for converting the format of originaldata so that the data reproducing apparatus 800 can reproduce the formatconverted data when the apparatus does not accept the format of theoriginal data.

Moreover, in the above embodiment, the case where the first signalprocessing unit 120 is composed of a DSP is explained. But, the presentinvention is not limited to this case. The first signal processing unit120 may be composed of another type of processors such as a CPU (CentralProcessing Unit), or partially or wholly by hardware.

Further, in the above embodiment, the case where the data processingapparatus 700 processes 10 frames of the data during one operating timeperiod is explained. But, the present invention is not limited to thiscase.

However, it is preferable that the number of frames to be processedduring one operating time period be large, because an overhead processsuch as the clock control process and the power supply control processis required to transfer from an operating time period to a waiting timeperiod or vice versa, and the load for performing the overhead processbecomes significantly heavy when frequent transferring is necessary.

Additionally, in this embodiment, the case where the start-up controlunit 180 performs the start-up control process in response to the datatransmit request signal sent from the sending data monitoring unit 190is explained. The data processing apparatus 700 of this embodiment,however, may comprise the trigger signal generating unit 170 as the sameas that of the data processing apparatus 100 of the first embodiment,and may make the start-up control unit 180 to perform the start-upcontrol process in response to the trigger signal generated in thetrigger signal generating unit 170.

INDUSTRIAL APPLICABILITY

The data processing apparatus according to the present invention isuseful especially for an audio player and a video player installed in amobile phone powered by batteries, and a mobile phone which can performan audio-visual processing.

1. A data processing apparatus for processing data to be transmitted toa data reproducing apparatus which reproduces received data stored in areceived data storage unit, comprising: a signal processing unit forreading out and processing data stored in data storage unit; a wirelesscommunication unit for wirelessly transmitting the data processed insaid signal processing unit to said data reproducing apparatus; a signalprocessing control unit for controlling said signal processing unit sothat said signal processing unit is able to operate intermittently byprocessing data within a time period less than a time period requiredfor reproducing data at said data reproducing apparatus; a clock/powercontrol unit for controlling a supply of at least one of clock signalsand power supplies to said signal processing unit and said signalprocessing control unit so that the power consumption of said signalprocessing unit and said signal processing control unit is decreased bycontrolling the supply of at least one of the clock signals and thepower supplies to at least one part of said signal processing unit andsaid signal processing control unit during a non-operating time periodof said intermittent operation; and a start-up control unit forcontrolling a start-up process to request a release of controlling thesupply of at least one of the clock signals and the power supplies to atleast one part of said signal processing unit and said signal processingcontrol unit to said clock/power control unit, and to requesttransferring to an operating time period of said intermittent operationto said signal processing control unit based on an amount of data storedin said received data storage unit.
 2. The data processing apparatusaccording to claim 1, further comprising a trigger signal generatingunit to estimate a timing when an amount of data stored in said receiveddata storage unit becomes less than a threshold amount and to output atrigger signal to said start-up control unit at the timing, wherein saidstart-up control unit performs said start-up process in response to saidtrigger signal.
 3. The data processing apparatus according to claim 1,wherein said start-up control unit performs said start-up controlprocess in response to a data transmit request signal sent from saiddata reproducing apparatus and received by said wireless communicationunit when the amount of data stored in said received data storage unitbecomes less than the threshold amount.
 4. The data processing apparatusaccording to claim 1, wherein said wireless communication unitwirelessly transmits data to said data reproducing apparatus each timethe data is processed by said signal processing unit.
 5. The dataprocessing apparatus according to claim 1, further comprising a sendingdata storage unit for temporarily storing the data processed by saidsignal processing unit, wherein said wireless communication unitwirelessly transmits the data processed by said signal processing unitand stored in said sending data storage unit to said data reproducingapparatus while said signal processing unit is processing another data.6. The data processing apparatus according to claim 1, furthercomprising a sending data storage unit for temporarily storing the dataprocessed by said signal processing unit, wherein said wirelesscommunication unit wirelessly transmits the data processed by saidsignal processing unit and stored in said sending data storage unit tosaid data reproducing apparatus independently from data processingprocessed by said signal processing unit.
 7. The data processingapparatus according to claim 1, wherein the data processing processed bysaid signal processing unit contains an encoding process of said data.8. The data processing apparatus according to claim 1, wherein the dataprocessing processed by said signal processing unit contains a decodingprocess of said data.
 9. The data processing apparatus according toclaim 1, wherein the data processing processed by said signal processingunit contains a sampling frequency converting process of said data. 10.The data processing apparatus according to claim 1, wherein the dataprocessing processed by said signal processing unit contains a spatialresolution converting process of said data.
 11. The data processingapparatus according to claim 1, wherein the data processing processed bysaid signal processing unit contains a frame rate converting process ofsaid data.
 12. The data processing apparatus according to claim 1,wherein the data processing processed by said signal processing unitcontains a format converting process of said data.
 13. The dataprocessing apparatus according to claim 1, wherein the data processingprocessed by said signal processing unit contains a protocol process ofsaid data in accordance with the communication protocol which saidwireless communication unit is compliant with.
 14. The data processingapparatus according to claim 1, wherein said clock/power control unitcontrols the supply of at least one of the clock signals and the powersupplies for at least one part of said signal processing unit and saidsignal processing control unit by performing at least one of loweringfrequencies of the clock signals, stopping supplies of the clocksignals, lowering voltages of the power supplies and stopping suppliesof the power supplies for at least one part of said signal processingunit and said signal processing control unit.
 15. A data processingmethod in a data processing apparatus of processing data to betransmitted to a data reproducing apparatus which reproduces receiveddata stored in a received data storage unit, comprising steps of: asignal processing step of reading out and processing data stored in adata storage unit; a wireless transmitting step of wirelesslytransmitting the data processed at said signal processing step to saiddata reproducing apparatus; a signal processing controlling step ofcontrolling said signal processing step so that said signal processingstep is able to operate intermittently by processing the stored datawithin a time period less than a time period required for reproducingdata at said data reproducing apparatus; a clock/power controlling stepof controlling a supply of at least one of clock signals and powersupplies so that the power consumption is decreased by controlling thesupply of at least one of the clock signals and the power suppliesduring a non-operating time period of said intermittent operation; and astart-up controlling step of controlling, a start-up process to requesta release of controlling the supply of at least one of the clock signalsand the power supplies and to request transferring to an operating timeperiod of said intermittent operation on an amount of data stored insaid received data storage unit.